Peugeot 405. Manual - part 31

Choke pull-down setting 
(Solex carburettor)

24 Pull the carburettor choke linkage to fully
close the choke valve, and hold the linkage in
this position.
25 Attach a hand-held vacuum pump to the
choke pull-down diaphragm, and apply a
vacuum to the diaphragm so that the
diaphragm rod is pulled fully into the
diaphragm body. In the absence of a vacuum
pump, the rod can be pushed into the
diaphragm with a small screwdriver.
26 With the rod fully retracted, use the shank
of a twist drill to measure the clearance
between the edge of the choke valve and
bore, and compare this to the clearance given
in the Specifications (see illustration). If
necessary, remove the plug from the
diaphragm cover and adjust by turning the
adjustment screw. Once the pull-down setting
is correctly adjusted, refit the plug to the
diaphragm cover and remove the vacuum
pump (where used).

Float height setting 
(Weber carburettor)

27 For float and level settings, remove the
float chamber cover and hold it vertically.

28 With the gasket in position, use a steel
rule or vernier calipers to check the height of
the floats. Bend the float tongue and
connecting bars if necessary.

Choke opening after starting 
(Weber carburettor)

29 Remove the air inlet from the top of the
carburettor. Pull the choke control knob out
fully to close the choke flap.
30 Disconnect the vacuum pipe from the
anti-flood capsule.
31 Connect a hand vacuum pump (or a
modified bicycle pump) to the capsule. Apply
vacuum (400 mm Hg approx.) to the capsule.
The choke flap should open far enough to
admit a drill shank or rod 5 mm in diameter.
32 Adjust if necessary by means of the screw
on the anti-flood capsule.
33 Disconnect the vacuum pump, remake
the original vacuum connection, and close the
choke flap.
34 Having adjusted the anti-flood capsule,
move the choke opening roller into the recess
of the cam as shown (see illustration).
35 Check that the choke flap opening just
admits a drill shank or rod 8 mm in diameter.
36 Adjust by turning the nut shown (see
illustration) after removing the carburettor.

14 Inlet manifold - 

removal and refitting

3

Note: Refer to the warning note in Section 1
before proceeding.

Removal

1 Remove the carburettor as described in
Section 12.
2 On TU engines, drain the cooling system as
described in Chapter 1, and disconnect the
coolant hose from the base of the manifold.
3 Disconnect the brake vacuum servo hose at
the manifold.
4 Disconnect the oil filler cap breather hose
from the manifold.
5 Unbolt the oil filler tube bracket.
6 Unscrew the retaining nuts, then
manoeuvre the manifold away from the head
and out of the engine compartment. Note that
on the TU engine there is no manifold gasket.
A gasket is however fitted on XU engines. On
XU engines note the centre clamp secured by
one nut (see illustration).

Refitting

7 Refitting is the reverse of the removal
procedure, noting the following points:

a) Ensure that the manifold and cylinder

head mating surfaces are clean and dry.
Fit a new gasket on XU engines, and
apply a thin coating of suitable sealing
compound to the manifold mating surface
on TU engines. Install the manifold and
tighten its retaining nuts to the specified
torque setting.

b) Ensure that all relevant hoses are

reconnected to their original positions and
are securely held (where necessary) by
their retaining clips.

c) Refit the carburettor as described in

Section 12.

d) Where applicable, refill the cooling system

as described in Chapter 1.

Fuel/exhaust systems - carburettor models  4A•9

14.6  Inlet manifold centre clamp 

on the XU engine

13.36  Choke mechanical opening

adjustment nut (4) (Weber carburettor)

4A

13.23  Throttle valve fast idle setting 

(Solex carburettor)

13.34  Checking the choke mechanical

opening (Weber carburettor)

Adjust until clearance X is as specified

Adjust screw Y until clearance X is as given in
the Specifications

a  Cam     3  Roller

13.26  Choke pull-down setting (using a

screwdriver to retract the diaphragm rod)

(Solex carburettor)

15 Exhaust manifold - removal

and refitting

3

Removal

1 Disconnect the hot-air inlet hose from the
manifold shroud and remove it from the
vehicle (see illustration).
2 Slacken and remove the retaining screws,
and remove the shroud from the top of the
exhaust manifold (see illustration).
3 On TU engine models apply the handbrake
then jack up the front of the vehicle and
support on axle stands (see “Jacking and
Vehicle Support”).
4 Undo the nuts/bolts securing the exhaust
front pipe to the manifold, then remove the
bolt securing the front pipe to its mounting
bracket. Disconnect the front pipe from the
manifold, and where applicable recover the
gasket.
5 Where fitted, loosen the clamp nuts and
release the power-assisted steering and
coolant pipes from the brackets (see
illustration).
6 Undo the retaining nuts securing the
manifold to the head (see illustration).
Manoeuvre the manifold out of the engine
compartment, and discard the manifold
gaskets.

Refitting

7 Refitting is the reverse of the removal

procedure, noting the following points:

a) Examine all the exhaust manifold studs for

signs of damage and corrosion; remove
all traces of corrosion, and repair or
renew any damaged studs.

b) Ensure that the manifold and cylinder

head sealing faces are clean and flat, and
fit the new manifold gaskets (see
illustration). Tighten the manifold
retaining nuts to the specified torque.

c) Reconnect the front pipe to the manifold

using the information given in Section 16.

16 Exhaust system - 

general information, removal
and refitting

3

General information

1 The exhaust system sections are joined by
flanged joints or clamped cone joints. Except
on TU engines the manifold to downpipe joint
is of the spring-loaded ball type, to allow for
movement in the exhaust system. On TU
engines the spring-loaded joint is located at
the rear of the front pipe. On early models
earth straps are fitted between the underbody
and the exhaust system (see illustration).
2 The system is suspended throughout its
entire length by rubber mountings.

Removal

3 Each exhaust section can be removed
individually, or alternatively, the complete
system can be removed as a unit. Even if only

one part of the system needs attention, it is
often easier to remove the whole system and
separate the sections on the bench.
4 To remove the system or part of the
system, first jack up the front or rear of the car
and support it on axle stands (see “Jacking
and Vehicle Support”). Alternatively, position
the car over an inspection pit or on car ramps.

Front pipe

5 Undo the nuts/bolts securing the front pipe
flange joint to the manifold, and the single bolt
securing the front pipe to its mounting
bracket. Separate the flange joint and collect
the gasket or spring cup and springs.
6 Slacken and remove the nuts from the front
pipe rear flange joint, and recover the clamp
or  spring cups and springs. Withdraw the
front pipe from underneath the vehicle, and
recover the gasket.

Front pipe extension

7 Undo the nuts from the front pipe rear
flange joint, and the clamp bolts from the
extension pipe rear joint.
8 Withdraw the extension from under the
vehicle and recover the gaskets.

Intermediate pipe

9 Undo the clamp bolts at each end of the
intermediate pipe, then remove the pipe from
under the vehicle.

Centre silencer

10 Slacken the clamping ring bolts and
disengage the clamps from the front and rear
flange joints.

4A•10 Fuel/exhaust systems - carburettor models

15.1  Remove the hot-air intake hose . . .

15.5  Power-assisted steering and coolant

pipe clamps (arrowed) 

(XU injection engine shown)

16.1  Exhaust-to-floor panel earth strap

fitted to early models

15.7  New gaskets fitted to the exhaust

ports on the cylinder head (XU engine)

15.6  The exhaust manifold retaining nuts

(TU engine)

15.2  . . . then undo the three retaining

screws (arrowed) and remove the exhaust

manifold shroud (TU engine)

11 Unhook the centre silencer from its
mounting rubber and remove it from
underneath the vehicle.

Tailpipe and silencer

12 Slacken the tailpipe clamping ring bolts
and disengage the clamp from the flange
joint.
13 Unhook the tailpipe from its mounting
rubbers and remove it from the vehicle.

Complete system

14 Undo the nuts securing the front pipe
flange joint to the manifold, and the single bolt
securing the front pipe to its mounting
bracket. Separate the flange joint and collect
the gasket. Free the system from all its
mounting rubbers and lower it from under the
vehicle.

Heat shield(s)

15 The heat shields are secured to the
underside of the body (and on some models
to the fuel tank) by various nuts and bolts 
(see illustration). Each shield can be
removed once the relevant exhaust section
has been removed. If a shield is being

removed to gain access to a component
located behind it, it may prove sufficient in
some cases to remove the retaining nuts
and/or bolts, and simply lower the shield,
without disturbing the exhaust system.

Refitting

16 Each section is refitted by reversing the
removal sequence, noting the following:

a) Ensure that all traces of corrosion have

been removed from the flanges and
renew all necessary gaskets.

b) Inspect the rubber mountings for signs of

damage or deterioration, and renew as
necessary.

c) Prior to assembling the spring-loaded

joint, a smear of high-temperature grease
should be applied to the joint mating
surfaces.

d) Where joints are secured together by a

clamping ring, apply a smear of exhaust
system jointing paste to the flange joint,
to ensure a gas-tight seal. Tighten the
clamping ring nuts evenly and
progressively to the specified torque
setting, so that the clearance between the
clamp halves remains equal on either
side.

e) Prior to tightening the exhaust system

fasteners, ensure that all rubber
mountings are correctly located, and that
there is adequate clearance between the
exhaust system and vehicle underbody.
Move the system side-to-side, and up-
and-down, to ensure it will not hit
anything when the car is moving.

Fuel/exhaust systems - carburettor models  4A•11

16.15  Heat shield on the underside 

of the fuel tank

4A

4B

System type

XU5 (BDZ and BDY) engine  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Magneti Marelli G5 single-point

XU5 (BDY) engine  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Magneti Marelli G6 single-point

TU3 (KDX) and XU9 (DDZ) engine  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Solex Fenix 1B single-point

TU3 (KDX) engine  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bosch Monotronic MA3.0 single-point

Fuel pump

Type

 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electric, external (early models) or internal (later models)

Pump delivery pressure:

Fenix 1B, MM G5 and MM G6 systems  . . . . . . . . . . . . . . . . . . . . . . .

0.7 to 0.8 bars

Bosch MA3.0 system  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.0 ± 0.1 bars

Pump delivery:

Fenix 1B and Bosch MA3.0 systems  . . . . . . . . . . . . . . . . . . . . . . . . .

370 cc per 15 seconds

MM G5 and G6 systems  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

360 cc per 15 seconds

Fuel system data

Specified idle speed (not adjustable)  . . . . . . . . . . . . . . . . . . . . . . . . . . .

850 ± 50 rpm

Idle mixture CO content*  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Less than 0.5%

*Mixture is controlled by the electronic control unit, and cannot be adjusted.

Recommended fuel

Minimum octane rating  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

95 RON unleaded (UK unleaded premium). Leaded fuel must not be
used on models with a catalytic converter

Torque wrench settings

Nm

lbf ft

Inlet manifold nuts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8

6

Exhaust manifold nuts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16

12

Exhaust system fasteners:

Front pipe-to-manifold nuts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

22

Front pipe mounting bolt  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35

26

Front pipe-to-catalytic converter nuts  . . . . . . . . . . . . . . . . . . . . . . . .

10

7

Clamping ring nuts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20

15

Chapter 4  Part B: Fuel/exhaust systems -
single-point fuel injection models

Accelerator cable - removal, refitting and adjusting . . . . . . . . . . . . . . .4
Accelerator pedal - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . .5
Air cleaner air temperature control system - 

general information and component renewal  . . . . . . . . . . . . . . . . . .3

Air cleaner assembly and inlet ducts - removal and refitting  . . . . . . . .2
Air cleaner filter element renewal  . . . . . . . . . . . . . . . . . .See Chapter 1
Bosch Monopoint system components - removal and refitting  . . . . .15
Exhaust manifold - removal and refitting  . . . . . . . . . . . . . . . . . . . . . .18
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Exhaust system - general information, removal and refitting  . . . . . . .19
Fenix system components - removal and refitting  . . . . . . . . . . . . . . .14
Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1

Fuel gauge sender unit - removal and refitting . . . . . . . . . . . . . . . . . .10
Fuel injection system - depressurisation  . . . . . . . . . . . . . . . . . . . . . . .8
Fuel injection systems - general information  . . . . . . . . . . . . . . . . . . . .7
Fuel injection system - testing and adjustment  . . . . . . . . . . . . . . . . .13
Fuel pump - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Fuel tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
General information and precautions  . . . . . . . . . . . . . . . . . . . . . . . . . .1
Idle speed and mixture adjustment  . . . . . . . . . . . . . . . . .See Chapter 1
Inlet manifold - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . .17
Magneti Marelli system components - removal and refitting  . . . . . . .16
Throttle body - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . .12
Unleaded petrol - general information and usage  . . . . . . . . . . . . . . . .6

4B•1

Easy, suitable for
novice with little
experience

Fairly easy, suitable
for beginner with
some experience

Fairly difficult,
suitable for competent
DIY mechanic

Difficult, suitable for
experienced  DIY
mechanic

Very difficult,
suitable for expert
DIY or  professional

Degrees of difficulty

Specifications

Contents